riscv64: add freestanding port

README.md

@@ -24,7 +24,7 @@ Adding support for new architectures is easy, but you need to know assembly lang
 |    mips64    | ✓             |         |                       |
 |      ppc     | ✓             | ✓       |                       |
 |     ppc64    | ✓             | ✓       |                       |
-|    riscv64   | ✓             |         |                       |
+|    riscv64   | ✓             |         | ✓                     |
 |     s390x    | ✓             |         | ✓                     |
 |      x86     | ✓             |         | ✓                     |
 |    x86_64    | ✓             |         | ✓                     |

arch/riscv64/freestanding/bits.h

@@ -0,0 +1,48 @@
+#ifndef LIBUCONTEXT_BITS_H
+#define LIBUCONTEXT_BITS_H
+
+typedef unsigned long libucontext_greg_t;
+typedef unsigned long libucontext__riscv_mc_gp_state[32];
+
+struct libucontext__riscv_mc_f_ext_state {
+	unsigned int __f[32];
+	unsigned int __fcsr;
+};
+
+struct libucontext__riscv_mc_d_ext_state {
+	unsigned long long __f[32];
+	unsigned int __fcsr;
+};
+
+struct libucontext__riscv_mc_q_ext_state {
+	unsigned long long __f[64] __attribute__((aligned(16)));
+	unsigned int __fcsr;
+	unsigned int __reserved[3];
+};
+
+union libucontext__riscv_mc_fp_state {
+	struct libucontext__riscv_mc_f_ext_state __f;
+	struct libucontext__riscv_mc_d_ext_state __d;
+	struct libucontext__riscv_mc_q_ext_state __q;
+};
+
+typedef struct libucontext_mcontext {
+	libucontext__riscv_mc_gp_state __gregs;
+	union libucontext__riscv_mc_fp_state __fpregs;
+} libucontext_mcontext_t;
+
+typedef struct {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+} libucontext_stack_t;
+
+typedef struct libucontext_ucontext {
+	unsigned long uc_flags;
+	struct libucontext_ucontext *uc_link;
+	libucontext_stack_t uc_stack;
+	unsigned char __pad[128];
+	libucontext_mcontext_t uc_mcontext;
+} libucontext_ucontext_t;
+
+#endif

arch/riscv64/makecontext.c

@@ -23,7 +23,7 @@ extern void libucontext_trampoline(void);
 
 
 void
-libucontext_makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
+libucontext_makecontext(libucontext_ucontext_t *ucp, void (*func)(void), int argc, ...)
 {
 	libucontext_greg_t *sp, *regp;
 	va_list va;